William might be a son of William Adams, the father of Elizabeth and Sarah Ann Adams. Jacob, William's only surviving child, was living with Sarah Ann and her husband G. W. Shirer at the time of his death. Since he was a bachelor at the time of his infirmity, it would be only fitting that Sarah take him in being the only family he had left. Whether he was a nephew is only speculation but it would seem correct due to the age difference and that they took him in when he was no longer able to live on his own due to his heart trouble.

This would make William Sarah's brother but there is yet no evidence to support the connection.